1. Field of the Invention
This invention relates to xerographic and electrostatic copying processes, and more particularly, to processes by which indicia are placed on an elongated sheet of paper by such processes, and the elongated sheet is then subsequently Z-folded for storage and use of the imprinted indicia.
2. Brief Description of the Prior Art
Some types of widely used documents are printed upon elongated sheets of paper which are fan-folded or Z-folded for convenience of storage. By fan-folded or Z-folded paper is meant paper which is folded alternately about a score line or fold line in first one direction, and then in the opposite direction so that accordian-like pleats are formed in the sheet of paper, and the document can be compactly stored in folded form. Documents which are frequently stored in this form include computer printouts, electrocardiograms, business and accounting tabulations and well logs developed in the exploration and production of oil and gas.
It is often desirable that Z-folded documents of the type described be copied or reproduced. In the past such reproduction has usually been accomplished photographically. Efforts to copy elongated fan-folded documents of indeterminate length, such as well logs and electrocardiograms, using conventional copying machines which employ the xerographic process have encountered difficulty and have been time-consuming, since these machines are generally adapted to copy letter or legal size documents onto copy paper of the same size, and are not adapted for continuously feeding the elongated, fan-folded original document and the copy paper onto which the indicia from such documents is to be copied. In my co-pending U.S. patent application Ser. No. 907,922 filed May 22, 1978, now U.S. Pat. No. 4,185,760, I have disclosed a system which enables an elongated fan- or Z-folded original document to be continuously fed to a xerographic copying machine concurrently with the continuous feed of copy paper from a roll supported adjacent the copying machine. This system has been successfully employed to permit copies of the elongated Z-folded originals to be made in an expeditious and efficient manner.
It has been necessary, however, when using the system disclosed in my U.S. patent application Ser. No. 907,922, to further process the completed copies so as to place them in the Z-fold or fan-fold configuration in which such documents are customarily used and stored. In most facilities where copying in this fashion has been carried out, folding of the completed copies into the Z-fold or fan-fold configuration has been carried out manually. Such manual folding requires the exercise of care to be certain that each fold line is formed in the right place, since, unless the fold line extends precisely transversely of the elongated sheet, subsequent folding is out of alignment, and the completed fan-fold document is unsightly and does not fold up neatly to the compact form sought.